This book contains a selection of papers from a NATO Advanced Research Workshop entitled "Stochastic models of hydrological processes and their applications to problems of environmental preservation" convened in Moscow over the period 23-27 November 1998. The Workshop was unique in providing the first opportunity for over a decade for countries of the Russian Federation to interact with other countries across the world to discuss hydrological science issues relevant to environmental management. The contrasting schools of thought within the Russian Federation and with other countries proved a fascinating and valuable experience for those fortunate enough to attend. The scientific content of the Workshop was motivated by a number of concerns. Water is a key natural resource whose modelling and management is made complex by its inherent spatial unevenness and time variability. Traditional methods for investigating hydrological processes in nature employ stochastic modelling and forecasting. However these are not well developed with regard to (i) representing the characteristics of hydrological regimes, and (ii) investigating the influence of water factors on processes which arise in biological systems and those involving hydrochemical, geophysical and other processes.